Not according to fresh research from Stony Brook University in New York.
"After statistical adjustment for socio-demographic characteristics, there were no behavioral or cognitive differences at age 5 between children who bed-shared with a parent during their toddler years and those who did not," researcher Lauren Hale of Stony Brook tells the website LiveScience.
LiveScience reports that's good news for roughly a third of parents who believe it's OK to sleep with toddlers. The rest of the parenting community is evenly split, according to the website, between those who oppose and those who have no opinion one way or the other.
Those who oppose it argue that it will give the child developmental problems down the road.
But researchers followed 944 low-income toddlers and their parents beginning when the children were a year old. After two years, any developmental problems could be traced to other factors (socioeconomic status, parenting style, etc.) rather than bed-sharing.
There was virtually no developmental difference between children who slept with a parent and those who slept on their own, Hale tells LiveScience.
"Since we did not find a difference, this study suggests that bed-sharing patterns are not contributing to divergent developmental trajectories," she says.
The American Association of Pediatrics recommends against sharing bed with infants because of the risk of sudden infant death syndrome, but Hale says that has nothing to do with this study.
"Our finding is not in conflict with this recommendation, because our study looked at bed-sharing at ages 1, 2 and 3 (past the period of infancy)," she tells LiveScience.
Helen Ball, a researcher at Durham University in England, wasn't involved in the study, but tells LiveScience it's welcome news.
"The study is helpful in debunking the myth that bed-sharing is associated with negative developmental outcomes," she says.